Interlocking composite construction block improvements

ABSTRACT

Embodiments relate to an enhanced method for building walls by primarily reducing the time for assembly. The designs are for molded multi-segment plastic composite construction blocks that interlock horizontally, vertically and orthogonally with a clearance-fit, do not require mortar for structural integrity and are self-aligning. The blocks are molded out of natural-fiber reinforced recycled thermoplastic composites and are stronger and lighter than CMU&#39;s.

BACKGROUND Field of the Invention

The present invention relates in general to composite blocks for use in construction analogous to prefabricated concrete masonry units (CMU's) and in particular to construction blocks that will reduce the labor time and associated with constructing a wall.

Description of the Related Art

Concrete Masonry Units (CMU's) are a low-cost, durable, product used worldwide for simple wall construction. Even though the blocks are low in cost they are labor-intensive to install and require skilled, expensive installers due to their need for manual alignment and mortar for adhesion and structural integrity. In addition the typical concrete used in CMU's is brittle and very heavy. Because of these factors, installation cost can be up to 10 times the purchase cost of blocks for wall construction. Also, the mechanical properties of concrete block material (about 14 MPa compression strength and about 300 MPa tensile strength) require reinforcement for most applications, at least in some portions of a wall. Most of a CMU wall is not load bearing except for certain areas reinforced with rebar and filled with concrete as necessary for the application.

There are multiple inventions that have been listed in prior art regarding CMU's. For instance, U.S. Pat. No. 6,167,669B1 for a Concrete Plastic Unit (CPU) describes a clear, permanent form, for steel reinforced concrete structures. Sections of the clear form are factory extruded, from a clear polyvinyl chloride material, so as to make the assembly of the forms, the installation of the steel and utilities, and the inspections that are required, easier. The clear forms will protect the steel reinforced concrete structures from the elements that cause these structures to fail. The clear form consists of two factory extruded profiles that are totally different in shape. The sections that make up the form, can be modified, cut to any length or angle and assembled on site. It takes two sections, of one profile, to form both vertical sides of the form, and two sections, of the other profile, are horizontally inserted, between the vertical side sections, to create an elongated empty container. The assembled clear form is 73/4 inches wide and 8 inches high, and is open on four sides. The assembled units are installed horizontally, and can be stacked and connected, on top of one another, to conform to any design, for residential or commercial construction.

Another U.S. Pat. No. 6,213,754B1 is for a cementitious composition for the molding of ultralightweight, durable, large structural units comprising Portland cement, coal combustion byproducts, expanded or extruded polystyrene and water, and a modified block machine used in the manufacture of such structural units.

U.S. Pat. No. 4,566,238A for an energy conserving CMU describes a wall constructed to function as a passive thermal mass for energy storage permits enhanced solar heating and nocturnal cooling of the interior of a building using walls as disclosed. Use of an expansive insulating material, foamed in place, seals the wall to make it waterproof. Concrete masonry units having inner and outer cells are stacked to form the wall. A hardenable material poured into the inner cells of the masonry units moves both vertically and horizontally within the wall to form a rigid wall structure. Introducing insulation in fluid form into the outer cells adjacent to those containing the hardenable material disposes the insulation to lie essentially adjacent the thermal mass of the rigid inner wall structure.

U.S. Pat. No. 6,050,749A is for a Concrete masonry unit for reinforced retaining walls and describes a concrete masonry unit especially suited for use in soil reinforced retaining walls. The reinforced retaining wall is comprised of precast, concrete block masonry unit facing elements connected by suitable connectors to reinforcing members which extend from the facing elements into the adjacent reinforced soil to form a mechanically stabilized earthen wall construction. The connectors which affix the reinforcing members at their connecting ends to the facing elements comprise concrete poured into a part or all of certain of the void spaces within selective facing blocks, which concrete may or may not be reinforced and which concrete when dry and cured, envelops and secures the connecting ends of the reinforcement members to their corresponding blocks and forms anchors thereat. The novel masonry unit disclosed herein effectively provides maximum facing area per unit volume (weight) of block, always exceeding 4.0 m/m, which results in considerable cost savings per unit of retaining wall surface area over conventional wall constructions.

Another patent US20170016228A1 for Surface Reinforced Concrete Masonry Units issued to the University of Manitoba is for a wall formed of masonry block units abutted with one another in series within stacked rows. Each masonry block unit is a concrete body having two opposing exterior side walls defining respective portions of the assembly masonry wall. Vertical reinforcement channels are formed in the exterior side walls of each masonry block unit so as to be open laterally to the exterior. The reinforcement channels align with corresponding channels in the masonry block units in adjacent stacked rows to receive elongate reinforcement members, for example rebar, inserted laterally therein from the exterior surface of the assembly masonry wall. A bonding material can then be recessed laterally into the reinforcement channels so as to bond the reinforcement members to the masonry assembly.

Another patent US20130205688A1 describes prefabricated compound masonry units in lieu of build site-constructed elements, as well as methods of producing the same. One embodiment comprises a first course comprising hollow blocks laid end to end with adjacent ends adhered with mortar, the hollow blocks positioned such that the first course has a hollow core; at least one channel formed in a top surface of the first course, the channel having a length; and provisional reinforcement provided along at least a portion of the length of the channel and held within the channel with a bonding material different from the mortar. The provisional reinforcement provides tensile strength to the first course for transportation and handling of the first course from a fabrication location to a build location where the first course is configured to receive permanent structural masonry reinforcement in the hollow core at the build location.

U.S. Pat. No. 3,005,282A issued in 1958 discloses the original patent for Lego™ toy building blocks. The patent describes building blocks, strips, or similar building parts to be assembled without the use of additional elements provided with complementary holes, grooves, or protuberances, e.g. dovetails with primary projections fitting by friction in complementary spaces between secondary projections, e.g. sidewalls.

There are multiple additional solutions that have been presented in prior art. Although the cementitious solutions offer improvements over standard CMU's they still suffer from limitations of being heavy, having poor impact properties, require manual alignment, require mortar for structural integrity and in general require skilled labor for alignment and installation.

The specific gravity of most block concrete is about 2.4 while the specific gravity of the thermoplastic composite blocks disclosed in this invention is less than 1.4. Also, while it is difficult to numerically compare due to the typical sample size differences, the impact properties of most thermoplastic natural fiber composites are well known to be significantly higher than that of low cost block concrete. The lower weight and better impact of natural fiber thermoplastic composites as described in the disclosed invention allow the molding of complex geometry with shells as thin as 3 mm. A block with similar shell thickness molded out of low cost block concrete would have significant breakage during transportation and installation.

A significant part of the structural integrity of standard CMU's and the prior art referenced here is due to the mortar. Unreinforced concrete walls perform poorly during earthquakes due to the low elongation before breaking which is typically significantly less than 0.5% while natural fiber thermoplastic composites show strains of between 2 and 6% before breaking. The disclosed invention does not require mortar for structural integrity due to the interlocking nature of the blocks. In addition to the lack of mortar they will align nearly perfectly due to the precise nature of a molded thermoplastic composite (typically less than +/−0.5 mm) and the disclosed design.

With respect to plastic building blocks such as Lego™ and other similar solutions disclosed herein and elsewhere, the significant differences are thermal expansion, creep, nature of assembly and geometry. Lego's and other similar blocks interlock through an interference fit where one or both parts deform during mating. This is possible with parts made of pure thermoplastics which can deform significantly before breaking (usually greater 10%) whereas thermoplastic composites like the design disclosed in this patent will typically break or be damaged at the deformation required for this kind of mating. The blocks in the disclosed invention mate with a clearance fit where no deformation is necessary.

Most thermoplastics like those used in Lego blocks have linear thermal expansion coefficients much greater than 0.0009/° C. Using a thermoplastic like this in large assemblies can exhibit significant deformations with normal temperature changes in building applications. These deformations can cause failure over time in the plastic or failure of the sealant or large gaps to appear depending upon if the assembly was made when the blocks were cold or warm. This effect is insignificant with small parts that are small. By contract the ideal thermoplastic natural fiber composite disclosed in this invention has a coefficient of thermal expansion less than 0.0002/° C. and will not exhibit this problem the same extent.

In addition to high thermal expansion, pure thermoplastics like those used in Lego™ blocks will have a tendency to creep. Especially with low-cost thermoplastics like polypropylene and polyethylene the creep can be significant under minimal loads at the temperatures seen in normal building applications. The same thermoplastics reinforced with about 50% natural fibers will typically exhibit an order of magnitude less creep.

Another significant difference between Lego™ blocks and the disclosed invention is the form of the molded blocks. Lego™ blocks are open on one side whereas the blocks in the disclosed invention are molded completely hollow. In addition Lego™ blocks interlock with an interference fit between the pins and the sidewall whereas the blocks in the disclosed invention interlock with lips and insets around the entire perimeter of each segment. The disclosed invention also has identical segments that can work on their own if separated, unlock Lego™ blocks. Also, Lego™ blocks do not have reinforcement capabilities provided by the holes in the disclosed invention or the interior accessibility provided by the open geometry of the disclosed invention.

The referenced current solutions that exist in the marketplace today, have difficult and time-consuming procedures for constructing walls. They are labor-intensive to install and require skilled, expensive installers due to their need for manual alignment and mortar for adhesion and structural integrity. Or, they are not suitable for the demanding requirements for most exterior wall applications.

None of the previous inventions and patents, taken either singly or in combination, is seen to describe the invention as claimed herein. Hence, the inventor of the present invention proposes to resolve and surmount existent technical difficulties to eliminate the aforementioned shortcomings of prior art.

DETAILED DESCRIPTION

Detailed descriptions of the preferred embodiment are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure or manner.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting the invention. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well as the singular forms, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof.

The use of the term“horizontal” is intended to mean the direction along the length of a wall. The use of the term“vertical” is intended to mean the direction perpendicular to the base plane of the installation, typically the ground. The use of the term“orthogonal” is intended to mean the direction 90 degrees to the horizontal direction of the wall. The use of the term “segment” is intended to mean a portion of a block that is equal in dimensions and form as all other segments that are connected laterally in a block. The use of the term“shell” is intended to mean the wall thickness of an individual block. The use of the term“wall” is intended to mean a barrier or planar separation in addition to the traditional meaning of the term. The term“wall thickness” is intended to mean the thickness of an entire block segment. The use of the term “CMU” is intended to mean the concrete masonry unit used in traditional concrete wall construction. The composition percentages referenced in this patent are all weight percent (%). Wood fiber is understood to be from trees such as pine, fir, bamboo etc. and not annual growth plants. The wood fiber referenced in this patent can be that recovered from pulp mill wastewater and contain adhered contaminants such as Calcium Carbonate. An“clearance fit” is intended to mean when there is a gap between pieces or parts pace making an assembly without having to deform either part like that in an interference type of fit such as a snap or press fit.

The present invention is intended to provide a methodology for reducing the labor cost associated with building walls similar to what would be constructed using concrete masonry units (CMU's). The design is for a multi-segment construction block that interlocks horizontally, vertically, and orthogonally, does not require mortar and is self-aligning.

The dimensions of the block as per its preferred embodiments are proposed to be similar to those of commercially available CMU's (FIG. 1 ) which are typically used to construct walls approximately 150 mm, 200 mm or 300 mm thick. The dimensions are not restricted to those listed here and can be anything that is manufacturable. FIG. 1 shows the orientation of a typical CMU with the end of a block (101) and the exposed face (102) of a block.

The block in the present invention is segmented with the width or thickness (201) of each segment equal to the length of each block segment (202). The length of the block (203) is an even multiple of the segment length. FIG. 2 shows a block with 3 segments. The exposed height of the block and segment (204) is normally the same as the segment length and width but can be any height.

Each segment has a male lip (205), (301) and a female inset (401) that span the perimeter of each segment and interlock vertically in a clearance fit with the male lips fitting into the female insets of each block. While the lip and inset are shown in FIG. 4 to span the entire perimeter of each segment it is not necessary and depends of the structural requirements of the particular application.

Each segment can have holes oriented horizontally (206) in the lip and inset areas so that when the blocks are interlocked the holes align horizontally. The holes are intended to accommodate rebar, bolts, rivets or pins to provide additional vertical and horizontal reinforcement as necessary. Each hole adjoining two blocks can have a bolt, rivet or other fastening device to firmly join only the two adjoining blocks. The holes can also be used as passages for wire, conduit and pipe to supply utilities along a wall. Additionally the blocks can have vertical passages (207) that can be used for mechanical reinforcement as necessary or as passages for utilities. Each segment is hollow and aligns with the segment below it allowing for clear passage from the top of the wall to the bottom. This passage can be filled with concrete or rebar or other reinforcing material as needed for the structural requirements of the application or can be filled with loose insulating material such as foam, rice hulls, cellulose, soil, rocks, etc. Block shell thicknesses (301) can be varied with the mold depending upon the mechanical requirements of the application and are typically less than 25 mm.

The blocks do not require mortar or sealant or adhesive for structural integrity but they can be used between blocks during installation for additional structural reinforcement or weatherability as necessary. FIG. 3 shows the top of an individual segment with channels for (302), (303) for sealant, adhesive, an O-ring or gasket. FIG. 4 shows a corresponding female inset (401) on an individual segment.

FIG. 5 shows the interlocking detail of assembled blocks with the male lip (501) and female inset (502) as well as the location of a horizontally located hole (503) for reinforcement or for a passage.

FIG. 6 shows two interlocking blocks with offset segments. While the blocks can be installed without offsetting the segments, an offset will provide additional structural integrity (especially in shear) as well as provide automatic alignment for the wall section.

FIG. 7 shows two interlocking blocks oriented orthogonally to make a comer.

Because the blocks have multiple segments, individual segments may be necessary to complete a wall section and make the blocks line up vertically even at the end. Individual blocks may be manufactured for this purpose or multi-segment blocks can be cut between segments to make single segment blocks. FIG. 7 shows a wall section utilizing a single segment block (801)

FIG. 9 shows a version of the block with an end face that has a vertical protrusion (901) that can be used to complete walls where a window or door opening is desired. The protrusion can be used to aid in the installation of windows or doors by providing a fastening guide. Additionally, special blocks can be made that have protrusions similar to (901) but located on the exposed top or bottom of a block where a window or door will be installed. Special blocks with sealed top or bottom surfaces may also be fabricated for starting the bottom of a wall or terminating the top of a wall but with a corresponding interlocking lip or inset to allow connecting with the corresponding blocks above or below.

Blocks can also have ports for water fixtures or wiring outlets as desired which can be configured from the inside of a block due to the accessibility provided by the hollow nature of each segment.

FIG. 10 shows the exposed face of a block with optional chamfers (1001) that may be desired to aid in sealing the wall from water intrusion.

To compete with CMU's the blocks need to be made from a low-cost material with strength equal or greater than that of concrete and have a low coefficient of thermal expansion. The blocks may be made by compression molding, blow molding, roto-molding or injection molding with some post-molding operation such as hole drilling or eliminating exterior molding draft necessary.

Although any moldable material can be used for this invention, probably the best mechanical properties per unit cost would be a natural fiber reinforced thermoplastic composite. The ideal material would be molded from a composite of natural or synthetic fibers (jute, wood, flax, kenaf, cotton, hemp, bamboo, cellulose, ramie, banana, etc.) and thermoplastics (polyolefins, nylon, PVC, polyesters, PLA, etc.) The ideal natural fiber thermoplastic composite material would have a compression strength greater than 60 MPa and a coefficient of linear thermal expansion (CLTE) less than 0.0002/° C. With a compression strength of >4 times that of the typical concrete block material (about 14 MPa), these natural fiber thermoplastic composite materials will allow the design of a block based on compression strength with ¼ the shell thickness of a typical concrete block if creep is not an issue.

The natural fiber composite formulation can include additives such as pigments (iron and other metal oxides, zinc ferrite, carbon black, titanium dioxide, etc.), UV light stabilizers (HALS, titanium dioxide, carbon black, nickel quenchers, benzophenones, benzotriazoles), antioxidants (hindered phenols, phosphites, thioesters, heat stabilizers; (organophosphites, hindered phenols), fungicides (zinc borate, microban), coupling agents (maleated polyolefins, maleic acid grafted styrene-ethylene-butadiene, silanes) and fire retardants (magnesium hydroxide, alumina trihydrate, borates). If the exposed part of the board is coated or not exposed to light or fire, the UV stabilizers, pigments and fire retardants are not necessary.

Alternatively, depending upon the demands of the application, the blocks can be made from recycled plastics including polyolefins, nylon, PVC, polyesters and mixtures thereof. With mixtures of different types of plastic a suitable coupling agent or compatibilizer such as a silane or maleic acid grafted polymer or suitable block copolymers containing segments that are compatible with the different polymers in the mix. Styrene ethylene butylene styrene triblock copolymer (SEBS) is one compatabilizer that can improve properties of polymer blends. Natural, synthetic or mined particles such as talc, calcium carbonate, clay, mica, carbon and nanoparticles of these minerals, rice hulls, flax shive, wood sawdust, bagasse, core from hemp or kenaf, etc. may also be used instead of fibers. Recycled natural and synthetic fibers recovered from mattresses, furniture or carpets will also work.

A more typical natural fiber thermoplastic composite with recycled plastic and fillers rather than fibers might have coefficient of linear thermal expansion less than 0.0003/° C. and compression strength greater than 40 MPa which would be suitable for many block applications.

In some instances, synthetic fibers such as glass, Kevlar and basalt may be cost effective as well as using a thermoset resin with catalyst such as an epoxy or polyester resin.

If creep is an issue, it may be desirable to cross-link the thermoplastic to prevent movement, especially under sustained loads and high temperatures. High density polyethylene is particularly suitable for cross-linking and can be performed in the mold if the temperature of the composite in the mold is high enough for the cross-linking to initiate. There are many cross-linking agents but for high density polyethylene (HDPE), tert butyl cumyl peroxide (BCUP) is commonly used at a composition of 2% of the weight of the polyethlene. Polypropylene and other thermoplastics have their particular cross-linking agents that may also be suitable for molding thermoplastic natural fiber composite blocks.

While specific embodiments have been shown and described, many variations are possible. With time, additional features may be employed. The particular shape or configuration of the platform or the interior configuration may be changed to suit the system or equipment with which it is used.

Having described the invention in detail, those skilled in the art will appreciate that modifications may be made to the invention without departing from its spirit. Therefore, it is not intended that the scope of the invention be limited to the specific embodiment illustrated and described. Rather, it is intended that the scope of this invention be determined by the appended claims and their equivalents.

The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in various embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter.

SUMMARY

In light of the disadvantages of the prior art, the following summary is provided to facilitate an understanding of some of the innovative features unique to the present invention and is not intended to be a full description. A full appreciation of the various aspects of the invention can be gained by taking the entire specification, claims, drawings, and abstract as a whole.

The primary desirable object of the present invention is to provide a novel and improved form of construction block analogous to Concrete Masonry Units (CMU's).

The main objective of the invention is to provide a remedy which poses improvement by having an improved methodology that can be used worldwide for construction of durable and low-cost walls.

It is further the objective of the invention to provide a methodology which minimizes the labor cost associated with constructing a block wall

It is also the objective of the invention to provide a design for a multi-segment construction block that interlocks horizontally, vertically and orthogonally, and does not require mortar and is self-aligning.

It is also the primary objective of the invention to provide a solution that is ecological by using recycled plastic which has low embedded energy and locally produced natural fibers or agricultural waste.

It is further the objective of the invention to provide a solution which is easy to use and does not require specialized training.

It is moreover the objective of the invention to provide solution which is cost effective to install and has cost effective over the life of the construction.

Thus, it is the objective to provide a new and improved solution for effective building blocks in applications where Concrete Masonry Units (CMU's) are typically used. Other aspects, advantages and novel features of the present invention will become apparent from the detailed description of the invention when considered in conjunction with the accompanying drawings.

This Summary is provided merely for purposes of summarizing some example embodiments, so as to provide a basic understanding of some aspects of the subject matter described herein. Accordingly, it will be appreciated that the above-described features are merely examples and should not be construed to narrow the scope or spirit of the subject matter described herein in any way. Other features, aspects, and advantages of the subject matter described herein will become apparent from the following Detailed Description, Figures, and Claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 discloses the appearance of a typical CMU as per illustrative embodiments of the invention.

FIG. 2 discloses a single multi-segment block as per illustrative embodiments of the invention.

FIG. 3 discloses a single block segment with interlocking male lip around the segment perimeter as per illustrative embodiments of the invention.

FIG. 4 discloses a single block segment with interlocking female inset around the segment perimeter as per illustrative embodiments of the invention.

FIG. 5 discloses details of an interlocking male lip and female inset in an assembled wall segment wall as per illustrative embodiments of the invention.

FIG. 6 discloses the two offset interlocking 3-segment blocks as per illustrative embodiments of the invention.

FIG. 7 discloses two orthogonally interlocking 3-segment blocks forming a corner as per illustrative embodiments of the invention.

FIG. 8 discloses the two offset interlocking 3-segment blocks with single segment block to terminate a wall as per illustrative embodiments of the invention.

FIG. 9 discloses a single segment block with a protrusion on an end face for locating windows or doors as per illustrative embodiments of the invention.

FIG. 10 discloses the chamfers on the exposed face of a block as per illustrative embodiments of the invention.

DETAILED DESCRIPTION (CONTINUATION IN PART)

The blocks disclosed in paragraphs 20-42 above and in FIGS. 2-10 can meet most of the mechanical requirements for constructing a typical block retaining wall or building wall when made out of a natural fiber thermoplastic composite with between about 40 and 70% natural fibers such as hemp, kenaf, flax, cotton, jute, wood fiber or particles such as wood flour or dust, rice hulls, peanut shells, hemp core, or any other agricultural fiber or particle including mixtures thereof. The thermoplastic content that is most feasible is between 30 and 60 weight percent depending on the viscosity and fiber wetting requirements.

Design limitations of the construction blocks disclosed in FIGS. 2-10 and described in paragraphs 20-42 above include limited water vapor permeability; potential water intrusion through block to block joints; cooling problems with molding the thick interior walls; the need for a cap and base to initiate and terminate wall sections and potential problems with creating horizontal holes in the lips and insets.

The blocks in FIGS. 2-10 show holes in the lips for passing conduit, rebar, wiring, etc. While the blocks can be supplied with pre-drilled holes in select locations, there are many more possible locations for holes that would be difficult to predict based on application. Because it would be difficult for the user to drill holes that perfectly align with adjoining blocks it may be more practical to supply the blocks with some pre-drilled holes as well as markings on the blocks for the user to drill holes. The markings would show the near-perfect locations to drill the holes. The markings could be molded into the block or applied after the molding with a scribe, punch or printing for example. This way the user has many more options for holes that could easily be realized using a long drill bit. The holes may be on the outside as well as inside of the block on any part of a lip or inset. In addition, indentations or markings can be molded in or added post-molding on any part of the block to be used as guides for grippers or post-molding robots or routers to accurately machine holes or trim draft, flash or adjust the dimensions of the blocks. FIG. 11 shows a single segment block with markings to indicate potential hole locations (1101).

Molding a thick part such as the interior walls of the construction block described above in paragraphs 20-42 can be costly due to the time required to cool quickly enough to prevent burning or to not deform during de-molding or cooling. One solution would be to have ribs on all or some of the interior walls. This would provide additional surface area for cooling while maintaining the wall stiffness. FIG. 11 shows the interior of a block with ribs (1102). The ribs may be on all or just the interior walls of the block. To aid in cooling the interior walls may also be thinned to aid in cooling without ribs.

A common problem with synthetic building materials is their inability to ‘breathe’. Temperature and moisture differences between wall, roof, ceiling or floor layers can result in condensation and over time contribute to biodegradation of building components. A breathable material is often desirable such as in Tyvek house wrap that is impermeable to liquid water but permeable to water vapor. Synthetic construction blocks with low moisture permeability such as those described in paragraphs 20-42 may inhibit vapor transmission through walls and contribute to condensation inside walls, especially if the joints are sealed or the fit is tight and there are humidity and temperature differences between the sides of a wall. A solution to this problem can be holes drilled in the block walls at an inclination so that water-vapor can diffuse but liquid water won't flow into the block. FIG. 12 shows the wall of an individual block with holes sloped down from inside the wall (1201) to the outside block surface (1202) to equalize humidity between inside the wall and outside the wall without liquid water intrusion. These holes can be located anywhere on a block surface. While the holes described above and shown in FIG. 12 can mitigate humidity differences across walls, if the block joints do not need to be sealed, the small inter-block air gaps may be sufficient to prevent humidity differences.

One difference between a concrete block like that disclosed by Moroschan in U.S. patent application Ser. No. 13/569,954 is that the block inset and lip are not the same thickness. Most all the existing technologies using concrete make it difficult to have a thin lip on the exterior of the block due to the brittleness of concrete. The materials disclosed herein permit the molding of blocks with interior lip thickness (1203) and exterior lip thickness (1204) the same thickness. With the interior and exterior lip thicknesses being the same they are each, by default, half the block body wall thickness (1205).

To initiate or terminate a wall made from the blocks described in paragraphs 20-42 and FIGS. 2-10 , special base and cap moldings can be made that fit onto the bottom or top of an installed wall. FIG. 13 shows a 2-segment cap molding and FIG. 14 shows a 2-segment base. These would be molded out of the same material as the blocks and with the same width (1301, 1401) and length (1302, 1402) of the blocks but have a sealed web (1303, 1403) that prevents water intrusion through the top of a wall with the cap and the base provides a structural base for a wall. The cap and base can have multiple segments and holes in the lips and insets for reinforcement just like the blocks. The cap and base webs may be any thickness that is structurally necessary and have ribs, if necessary, to add stiffness. Also, in certain situations it may be useful to have a block cap or base molded into the block so that purchasing a separate block is not necessary. While the separate block cap spans two different blocks and prevents water intrusion between blocks, as well as aids in the structural integrity of an installation, in some situations it is not necessary.

While the thermoplastic composite blocks described in paragraphs 20-42 above have the ability to sustain large loads, even more than concrete with some formulations, they can creep or deform if the load is maintained over long periods of time and with high temperatures. As an alternative to cross-linking or using an expensive engineering resin, a woven or non-woven mesh can be molded into the block. Using insert molding or other similar techniques a woven or non-woven mesh of synthetic or natural fibers such as PET, glass, Kevlar, basalt, nylon, jute, hemp, kenaf, flax, cotton or alternatively a plastic or metal sheet can be molded onto the outside surface of the block by placing the mesh or sheet in the mold before the material charge and upon compression the mesh will be embedded in the surface of the block. The mesh can be molded into the inside or outside surface. FIG. 15 shows a single segment block with a woven-mat (1501) molded to the outside surface of a block.

Blocks with a mesh as described above and shown in FIG. 15 but made of electrically conductive metal and of sufficient wire density can also serve as a Faraday cage and be used to construct a house shielded from electromagnetic fields. A similar mesh can also be molded into the head-lap (1602) or exposure (1601) of roofing panels like that disclosed in U.S. Pat. No. 6,983,571 (FIG. 16 ) to serve as a Faraday cage for a roof and together with blocks make a whole-house Faraday cage. The conductive metal mesh should be between 1 and 15% of the formulation to be effective.

To improve impact performance, a synthetic or natural fiber woven or non-woven mesh may be molded into the head-lap or exposure of a composite roofing product such as that disclosed in U.S. Pat. No. 6,983,571 and help achieve a UL2218 impact rating at between 1 and 5% of the head-lap or exposure weight by terminating surface crack propagation. Natural fibers such as cotton, hemp, jute, or kenaf and synthetic fibers such as Kevlar, Nylon or PET, are examples of these fibers.

To improve flame spread, a glass, basalt or any other fire-resistant woven or non-woven fiber mesh can be molded onto the exposed surface of a block as described above and shown in FIG. 15 . A woven glass fiber mesh can improve the ASTM E-84 flame spread rating at between about 1 and 5% of the block weight. A 6 ounce per square yard standard woven fiberglass mesh would be an example of a suitable fiber mesh.

If a similar mesh is molded onto a surface of a composite roofing panel like that described in U.S. Pat. No. 6,983,571 (FIG. 16 ), it can improve the burning brand performance of a roofing assembly (ASTM E-108). Though it would affect the aesthetics if molded onto the exposed surface of the exposure (1601), if it is molded into the head-lap (1602) or the underside of the exposure at about 1 to 5% of the headlap or exposure weight it would help the burning brand performance without affecting the aesthetics. FIG. 16 shows a woven mat molded into the head-lap top surface (1602) of the composite roofing panel described in U.S. Pat. No. 6,983,571.

Wind-driven or heavy rain may cause water to move through the block-to-block junctions in a wall assembled with the blocks described above in paragraphs 20-42 and shown in FIGS. 2-10 and potentially into a living space or into the block cavity. To make the junctions more water resistant joint FIG. 17 shows a scalloped, corrugated or ribbed end face (1701) that would interweave with the adjoining block (with a corresponding matching texture) creating a tortuous path for water which would impede water moving between blocks. Also, the junctions faces between blocks stacked on top of one another can be inclined (1702) to help shed water. A 10-30 degree inclination from the horizontal is sufficient to divert a substantial amount of water.

Limitations of current material technologies for the natural fiber composite construction blocks described above in paragraphs 20-42 as well as natural fiber composite roofing products like in U.S. Pat. No. 6,983,571 and the railroad ties disclosed in U.S. Pat. No. 11,408,182 include high material cost, high product weight, poor fire performance, low impact performance and objectionable odor.

Laminated thermoplastic films are difficult to recycle or process and therefore normally landfilled or incinerated and are often free and can significantly lower the cost of natural fiber thermoplastic composite materials. These films can completely replace the thermoplastic content in certain thermoplastic composite formulations with the thermoplastics completely melted in processing or with the PET and Nylon un-melted resulting in a non-homogeneous mixture. The typical thermoplastic content is between 30 and 40% of a natural fiber thermoplastic composite suitable for the applications described herein. The non-thermoplastic coatings of a film such as paper, foil, SiO2 also will not melt and contribute to the non-homogeneity of the mixture. The un-melted foils, paper, nylon, and PET components can be up to 10% of the thermoplastic film composition and up to 4 weight % of the thermoplastic composite formulation. The non-melting films and coatings contribute to the impact strength of these products by terminating crack propagation. Also, because the blocks described above in paragraphs 20-42 and the roofing panel described in U.S. Pat. No. 6,983,571 only require adequate compression strength even source materials with poor properties can suffice, especially if the part thickness is increased to compensate for the poor properties.

Barrier films that will work as part of the thermoplastic component in many non-aesthetic applications include:

any combination of thermoplastic film including:

-   -   bi-axially oriented polypropylene (BOPP), cast         polypropylene(CPP), mono-oriented polypropylene (MOPP), oriented         polypropylene (OPP), nylon, vacuum metallized polyethylene         terephthalate (VMET) or any other metallized polyester,         metalized oriented polypropylene (MOPP), Saran®, polyethylene         terephthalate (PET);

combined with:

-   -   PET, and PE, metalized Barrier MET, high density polyethylene         (HDPE), low-density polyethylene (LDPE), and linear low-density         polyethylene (LLDPE);

along with any combination of tie layer including:

-   -   Ethylene-vinyl acetate (EVA), Ethylene-methyl acrylate (EMA),         Ethylene-acrylic acid (EAA), Ethylene-grafted-maleic anhydride         (AMP), polypropylene grafted maleic anhydride, HDPE, LDPE, PP,         PS, PVDC, nylon, PET Ionomers, EVOH, Cellulose;

and any combination of the following coatings including:

-   -   aluminum, paper, LDPE, PE, PET, Nylon, EVOH, EAA, PA, EVA, SiO₂.

Because most roofing products such as shingles, shakes, tile and slate have head-laps that are not visible, these films can be used as part of the thermoplastic content in the formulation for these applications without detriment. For example, FIG. 16 shows the composite roofing panel described in U.S. Pat. No. 6,983,571 with a head-lap (1602) that could benefit from using recycled thermoplastic films.

In addition to roofing products, these films can be used as all or part of the thermoplastic content in formulations used in construction blocks because construction blocks may be painted, covered with siding or stucco or be obscured with soil.

Molded railroad ties like those described in U.S. patent Ser. No. 11/408,182 may also benefit from the use of these films due to their low aesthetic requirements.

In addition to films with tie-layers and metallic coatings, plastic parts with thermoplastic elastomers (TPE) and silicone or rubber flexible coatings for handles and other housewares can be difficult to recycle and are often landfilled or incinerated as well. TPE's can include thermoplastic vulcanizates, thermoplastic polyurethane, thermoplastic rubber and styrenic based elastomers. While difficult to recycle, they can be a valuable addition to a head-lap formulation due to their ability to bind or couple different types of plastics, including un-melted nylons and PET. These TPE's at a level up to 10 weight percent of a composite roofing product head-lap, construction block or railroad tie formulation, will not only improve the commercial feasibility because of the low cost but because they can substitute for MAPE (maleic acid grafted polyethylene) coupling agent in a formulation and improve mechanical performance.

In addition to TPE's, thermoset elastomers such as silicone, latex or vulcanized rubber, can be part of a recycle stream and can be part of a formulation without detrimental affect up to about 10% of a composite block or roofing head-lap formulation providing a suitable coupling agent is used in the formulation as well.

One low-cost option for improving fire resistance and biodegradation resistance in natural fiber composites is Silica (SiO₂). A silica content of between 5 and 15 weight % in a natural fiber thermoplastic composite formulation can provide substantial fire resistance and help achieve a low flame spread. The silica can preferably be adhered to or embedded in the natural fibers but is also effective if distributed in the plastic matrix. The silica can be mined, sourced from natural materials or be synthetic fumed silica.

In addition to silica for fire resistance, natural or synthetic hollow, porous or low density spheres or particles can aid in the fire resistance of natural fiber thermoplastic composite formulations as well as reducing the density and weight of a natural fiber composite roofing product, construction block or railroad tie. In addition, these hollow spheres or particles will improve the insulating properties. Glass cenospheres or natural pumice (which is primarily silica) are two examples of these types of materials that can be added at between 5 and 20% to improve performance. The glass cenospheres preferably would have compression strengths greater than the molding pressure of typically >1500 psi.

Low cost recycled thermoplastics, especially post-consumer, can be contaminated with food or other waste and if not washed adequately can have an objectionable odor. For products that are installed in proximity to humans or even displayed in stores this may not be acceptable. Heating the product at an elevated temperature for a period of time can be used drive off volatile organic compounds responsible for the odors. Also, the addition and dispersion of activated carbon in a composite block or roofing formulation at between 1 and 5% can be an effective way of reducing objectionable odors if contaminated thermoplastics are used in the formulation.

Molding the segmented block described in paragraphs 20-42 and shown in FIGS. 2-10 can be difficult, especially with ejection with thin walls and minimal draft to conserve material. One remedy for this is a block with pins and holes for alignment and joining of the blocks.

FIG. 18 shows the top male side of a 2-segment construction block similar in structure to a standard CMU but with web sealing one face (1801) and pins (1802) for alignment and interlocking. Instead of lips and insets located around the circumference of a block segment as described above, pins are located around the circumference of each segment in a square pattern with equal spacing between orthogonal (1803) and lateral pins (1804). In FIG. 18 each segment has pins in a 5×5 matrix, for example. The number of pins in the matrix can be any number>4 and need to be in a square pattern offset from the pins around the circumference of the block. FIG. 18 shows the non-visible border (1805) between the two segments with equal dimensions.

The block shown in FIGS. 18, 19 and 20 are joined by pins and corresponding cavities through clearance fits as opposed to Lego™ which uses interference fits. This is because the resin used in molding Lego™ blocks is capable of significant deformation unlike the composite materials disclosed herein.

FIG. 19 shows the bottom side of the block shown in FIG. 18 with receptacles or cavities for the pins in a square pattern around the circumference of each segment that are designed for an clearance fit with the corresponding pins. The pin cavities should have the same spacing as the pins on the male side of the block. Although you cannot access an entire column of blocks and fill it with insulation like a standard CMU or the blocks described above, because one face is close off (1801) you can easily fill a block with insulation for example. These blocks with pins and a close face are more amenable to use as garden walls or retaining walls than a house where it isn't necessary to access the block interiors.

Because there are a plurality of discrete pins and receptacles (FIGS. 18 & 19 ), this design allows for a wide variety of both lateral and orthogonal offsets. FIG. 20 shows an assembly of two 2-segment blocks that are aligned with orthogonal (2001) and lateral (2002) offsets that are not the same dimensions as the segment-length in these same blocks.

The pins and cavities shown in FIGS. 18 and 19 can be easily molded into the blocks or only holes can be molded into the blocks and pins can be inserted into the holes in the face with the web. The pins can be metal, composite, plastic, wood or any other material with structural capabilities. Also, the pins can have threads or barbs that allow for one way installation and extraction difficult so that there is vertical reinforcement with a wall installation. The pins can be square, rectangular, cubic, trapezoidal, elliptical, cylindrical or any other easily molded shape. The receptacles are a corresponding shape that will accept the pins with a clearance fit or a fit in the case of screws or barbs that displace or cut some of the material in the joint.

Analagous to the cap and base disclosed in FIGS. 13 and 14 , the block described herein with pins and receptacles can also have associated an associated cap and base. The cap would have a sealed web without protruding male pins (1802) with pin receptacles on the underside in a pattern that will fit the male side of a block. The base would just be a sealed web with protruding male pins. Both the cap and base would have the same width as a block and length a multiple of a segment length.

In addition to blocks that interlock as disclosed herein, a simple CMU as shown in FIG. 1 which has two separate hollow chambers can work functionally and physically using the material formulations disclosed herein including the use of thermoplastic films with un-melted elements, carbon black for odor control, glass cenospheres for weight reduction and fire resistance and fiber meshes for impact and fire resistance. If the formulation includes thermoplastic films such as those described in paragraphs above, the generally thicker walls of a CMU can still be economically feasible due to the lower cost of recycled thermoplastic laminated films. The thicker walls of the standard CMU is generally needed to provide vertical support and weigh distribution between layers of blocks. To adhere layers of blocks of standard CMU's made of thermoplastic composites, a polyurethane or silicone based adhesive will work if the natural fiber or filler composition is >50% of the block weight and especially if the surfaces to adhere are sanded to expose the fibers.

To summarize, the laminated films described herein can be used in formulations for all of the block manifestations described herein as well as roofing panel head-lap formulations at about 20-70 weight %. If contaminated films are used in a block formulation, activated carbon can be used at between 1 and 5% of the formulation to help with odor control. Natural or synthetic fiber meshes can be used to improve impact resistance of blocks and roofing panels (on the underside of the exposure) at about 1-5% of the formulation. Fire resistant fiber meshes can be used to improve flame spread of natural fiber thermoplastic composite construction blocks and railroad ties and the burning brand performance of roofing panels at between 1 and 5% of the formulation. Glass cenospheres or pumice can be used to improve the fire resistance of the thermoplastic composite construction blocks described herein at between 5 and 20% of a formulation. Silica can also be used to improve the fire resistance of the thermoplastic composite construction blocks described herein or roofing panels referenced herein at between 5 and 15% of a formulation. Also, TPE's can be used as a substitute coupling agent for natural fiber composites made with recycled plastics at up to about 10% of the formulation.

An exemplary formulation for a block or roofing panel head-lap that does not have aesthetic requirements because it is painted or covered with siding is 5% Aluminum hydroxide, 1.5% maleic acid grafted polyethylene, 63% natural fibers or particles, 0.05% phenolic antioxidant, 0.05% organic phosphite antioxidant, and 30.3% thermoplastic blend where the thermoplastic film blend is comprised of: 2% un-melted nylon 6 film, 0.2% tie layer and 97.8% 50/50 LDPE/LLDPE blend.

An exemplary formulation for a block that is exposed to the elements and has aesthetic requirements is 5% Aluminum hydroxide, 1.5% maleic acid grafted polyethylene, 49% lignocellulosic natural fibers or particles, 10% SiO₂, 0.1% HALS light stabilizer, 0.05% phosphite antioxidant, 0.05% organic phosphite antioxidant, 4% Fe₂O₃/Fe₃O₄ pigment blend, and 30.4% thermoplastic blend where the thermoplastic blend is comprised of HDPE, LDPE and LLDPE.

An exemplary formulation for lightweight block or roofing panel head-lap that does not have aesthetic requirements because it is painted or covered with siding is 5% Aluminum hydroxide, 1.5% maleic acid grafted polyethylene, 63% natural fibers or particles, 0.05% phenolic antioxidant, 0.05% organic phosphite antioxidant, and 30.3% thermoplastic blend where the thermoplastic film blend is comprised of: 2% un-melted nylon 6 film, 0.2% tie layer and 97.8% 50/50 LDPE/LLDPE blend.

An exemplary formulation for a block that does not have aesthetic requirements because it is painted or covered with siding is 5% Aluminum hydroxide, 1.5% maleic acid grafted polyethylene, 60% natural fibers or particles, 0.05% phenolic antioxidant, 0.05% organic phosphite antioxidant, 3% activated carbon, and 30.3% contaminated thermoplastic film where the thermoplastic film blend is comprised of: 2% un-melted nylon 6 film, 0.2% tie layer and 97.8% 50/50 LDPE/LLDPE blend.

An exemplary formulation for a block that has high mechanical properties and can be molded with thinner walls and is not exposed to the elements is 7% Aluminum hydroxide, 1.5% maleic acid grafted polyethylene, 50% hemp bast fiber, 0.05% phenolic antioxidant, 0.05% organic phosphite antioxidant, and 41.4% recycled high density polyethylene.

BRIEF DESCRIPTION OF DRAWINGS (CONTINUATION IN PART)

FIG. 11 discloses the appearance of a single segment of an interlocking construction block with interior ribs to improve cooling and reduce weight and markings for locations of holes for through the block lips per illustrative embodiments of the invention.

FIG. 12 discloses the exterior wall cross section of an interlocking construction block with a hole for ventilation as well as the relative wall and lip thicknesses per illustrative embodiments of the invention.

FIG. 13 discloses the appearance of 2-segment block wall cap per illustrative embodiments of the invention.

FIG. 14 discloses the appearance of 2-segment block wall base per illustrative embodiments of the invention.

FIG. 15 discloses the appearance of a single-segment block with a mesh molded to the outside surface of the block per illustrative embodiments of the invention.

FIG. 16 discloses the location of a mesh molded onto the head-lap of a composite roofing panel per illustrative embodiments of the invention.

FIG. 17 discloses a corrugated end face and inclined junction face for shedding water on an interlocking construction block as per illustrative embodiments of the invention.

FIG. 18 discloses the male face of a 2-segment construction block with pins for alignment per illustrative embodiments of the invention.

FIG. 19 discloses the female side of a 2-segment construction blocks with receptacles for the alignment pins per illustrative embodiments of the invention.

FIG. 20 discloses an assembly of two, 2-segment construction blocks with pins and cavities for alignment with both lateral and orthogonal offsets per illustrative embodiments of the invention. 

1. A segmented plastic composite construction block with each segment length equal to segment width allowing for assembly of walls with blocks that can interlock horizontally, vertically and orthogonally with lips and insets that have a clearance-fit and are located around the perimeter of each segment; wherein each block has more than one adjoining equal dimension segment; wherein each segment has a male lip that fits into the female inset on the block segment above or below it; and wherein the lip thickness is equal to the inset dimension.
 2. The block in claim 1 wherein each segment has holes in the male and female interlocking parts that align horizontally allowing the passage of conduit, wiring, pipe, bolts, fasteners, rebar or other reinforcements.
 3. The block in claim 1 wherein the thermoplastic composite comprises about 25 to 50 weight % hemp fiber.
 4. The block in claim 1 wherein there are indications for drilling holes through the lips and insets.
 5. The block in claim 1 wherein a metal wire or synthetic fiber mesh is molded into the exterior surface of the block.
 6. The block in claim 1 wherein the horizontal mating surfaces of each segment are inclined about 5 to 30 degrees.
 7. Block in claim 1 wherein the thermoplastic composite comprises about 5 to 20 weight % glass cenospheres.
 8. The block in claim 1 wherein the thermoplastic composite comprises about 5 to 15 weight % silica.
 9. The block in claim 1 wherein the thermoplastic composite comprises about 0.5 to 5 weight % thermoplastic elastomer.
 10. The block in claim 1 wherein the thermoplastic composite comprises up to about 4 weight % un-melted thermoplastic film components.
 11. A molded, hollow, segmented thermoplastic plastic composite construction block with each segment length equal to segment width allowing for assembly of walls with blocks that can interlock horizontally, vertically and orthogonally with a web on the top face that has male pins around the perimeter of each segment at a regular spacing; a matrix of pins offset at this same spacing towards the center of the web of each segment and corresponding cavities located around the perimeter of the bottom, female face have a clearance fit with the corresponding pins.
 12. The block in claim 11 wherein the thermoplastic composite comprises about 25 to 50 weight percent hemp fiber.
 13. The block in claim 11 wherein a metal wire or synthetic fiber mesh is molded into the exterior surface of the block.
 14. Block in claim 11 wherein the thermoplastic composite comprises about 5 to 20 weight % glass cenospheres.
 15. The block in claim 11 wherein the thermoplastic composite comprises about 5 to 15 weight % silica.
 16. The block in claim 11 wherein the thermoplastic composite comprises about 0.5 to 5 weight % thermoplastic elastomer.
 17. The block in claim 11 wherein the thermoplastic composite comprises up to about 4 weight % un-melted thermoplastic film components. 